Overweight and obesity are the most prevalent health problems in the U.S. today, affecting more than 64% of adults, and contributing significantly to morbidity and mortality: There is substantial evidence that improving diet habits and increasing physical activity promote weight control, reduce disease risk, and enhance overall health. A health promotion program delivered at the worksite has numerous advantages, including the opportunity to reach a large number of people in a time-efficient and cost-effective manner. We propose to conduct a worksite intervention titled "Worksite Opportunities for Wellness" (WOW), which includes individual, group, and environmental components designed to promote healthier dietary and physical activity behaviors among university staff. The specific aims are to evaluate: (1) the feasibility of delivering our multi-component WOW program in 2 university worksites; (2) the efficacy of WOW on reducing the prevalence or severity of overweight and obesity; (3) the efficacy of WOW on improving risk factors for cardiovascular disease and type 2 diabetes; and (4) the impact of WOW on quality of life, absenteeism, and health care utilization. A delayed treatment design will be used, in which Site A has a 1-yr intervention with 1-yr follow-up, and Site B has a 1-yr control period followed by the 1-yr intervention. Assessments of weight, body mass index, body composition, waist circumference, lipids, glucose, fitness, quality of life, absenteeism, and health care utilization will be made at baseline and 6, 12, 18, and 24 months. The WOW intervention is comprised of a constellation of nutrition components, physical activity components, and incentives, including a weekly healthy snack cart, on-site Weight Watchers program, on-site exercise program, monthly healthy lunch seminars, healthier foods in vending machines and the cafeteria, free pedometers, colorful maps of walking routes, team competitions among coworkers, personal health reports, and several raffles.